1. Field of the Invention
The present invention relates to an elevator, and more particularly to an elevator having covers capable of reducing noise and vibration by minimizing a generation of vortex flows at an upper portion and a lower portion of the elevator during movements of the elevator in a hoistway.
2. Description of the Prior Art
In general, an elevator is used for transferring goods or passengers in high rise buildings. High rise buildings have been built up due to the developments of architecture techniques. Thus, elevators which are installed in the high floor buildings, specially elevators for passengers, have been required for operating at high-speed in order to transfer the passengers rapidly.
When the elevator is operated faster than specified speed in the hoistway, air which flows in the hoistway, causes turbulent flow around the elevator, thereby generates substantial noise in an inner space of the elevator.
Japanese Patent laid-open publication No. Hei6-329372, filed by Mashayuki, et al. on Jul. 30, 1993 and published on Nov. 29, 1994, discloses an elevator having a cover mounted on an outer surface thereof.
FIG. 1 is a perspective view of an elevator 10 having a cover according to the invention described in the Japanese patent laid-open publication issued to Mashayuki, et al., and FIG. 2 is a cross-sectional view of the elevator 10 shown in FIG. 1. Referring to FIGS. 1 and 2, the elevator 10 according to the above-mentioned invention includes a fixed supporting body 12 which is connected to a traction means, a cabin 20 for passengers, which is disposed on the supporting body 12 as to be supported by at least one of vibration-absorbing material 14, and a cover 30 which is mounted on the supporting body 12, including tapered sections 32 and 34 at an upper and a lower portions of the cabin 20 and for surrounding sides of the cabin 20 as to cover up tightly the cabin 20.
As described above, in the elevator 10 according to the invention of the above-mentioned publication issued to Mashayuki, et al., the air is made to flow along an outer surface of the cover 30 in hoistway for the elevator by tapering the upper and lower portions of cover 30 surrounding the cabin 20 so that the generation of the turbulent flows, which can create the noise, may be minimized. Furthermore, by providing a space between the cover 30 and the cabin 20, a vibration which is created due to the air flows is prevented from transferring from a wall 36 of the cover 30 to cabin 20.
In the elevator 10 having the cover 30 mounted on the cabin 20 thereof, however, while the air flows through a hole, which is perforated through a top portion of the cover 30 and makes a rope 40 connecting to the elevator 10 extended in order that the traction machine (not shown) moves up and down the elevator 10 in the hoistway, and the space defined between the cover 30 and the cab 20, this can create the turbulent flows. Therefore, there are disadvantages in that the noise and the vibration can be generated by the turbulent flows in the space defined between the cover 30 and the cabin 20 and may be transferred to an inner space of the cabin 20 of the elevator 10.
On the other hand, on an outer upper surface of the cabin 20 of the elevator 10, typically there are mounted an electric motor which generates force to open and close a door, rollers which receive the driving force from a power transmitting mechanism including a shaft and links and is fixed to the door at an end thereof, mechanical apparatus, such as rails, for guiding the rollers to be moved, and electric apparatus, such as a controller, for controlling the electric motor. Such machine and the electric apparatus, which are mounted on the upper portion of the cabin 20, are made to be repaired and periodically maintained by service men.
In the elevator 10 according to the above-described invention, when the machine and the electric apparatus on the cabin 20 are to be repaired or maintained, special tools are required to separate cover 30 from cabin 20, and it takes a long time to remove the cover 30 from cabin 20 since the cover 30 made in one piece surrounds the cabin 20.
Furthermore, to make the cover 30, a high-technical method is required because the cover 30 is large and in one piece with curved portions and flatted portion, thereby increasing the cost of manufacturing the cover 30.
Also special equipments and technique are required to transfer the cover 30, because it is large and in one piece, to a certain building in which the elevator 10 is installed and to surround the cabin 20. Furthermore, it takes a long time to install the cover 30 on the cabin 20.
A buffer generally is disposed on the bottom surface in the hoistway of a building in which the elevator typically moves vertically. In the elevator according to the conventional art, then, there is a problem in that the lowest portion of the cover collides with the buffer. To prevent the cover from colliding with the buffer, it is possible to extend the hoistway downward from the lowest floor of the building. However, there is disadvantages in that time for establishing the building is extended and the cost of installing the elevator is increased.